Raghu Murtugudde

How can forecasting of extreme rainfall events be improved?
Greater precision in forecast of extreme events is critical. priyad posted 1 year 10 months ago

Mumbai, July 5 (India Science Wire): On July 2, the Maharashtra government decided to close private and public schools in Mumbai based on IMD’s rainfall forecast which predicted "intermittent rain in city and suburbs, with heavy to very heavy rainfall at a few places for the next 24 hours." The 24-hour period from 8:30 am of July 1 to July 2 saw a total of 375 mm of rain and it

Villages under water which gushed in as Cyclone Aila struck south 24 Parganas. Image credit: Anil Gulati from IWP Flickr. Image used for representational purposes only.
Extreme rainfall events need not lead to floods
Many hydraulic factors such as physiography, drainage, catchment size and vegetation cover are critical for peak flood conditions. arathi posted 2 years 3 months ago

It has been reported that extreme rainfall events are increasing over India and widespread floods have increased threefold over the last several decades from an average of two events per year to six events per year. But the link between extreme rainfall events and rising incidence of floods remains tenuous.  

Many hydraulic factors influence occurrence of floods. (Pic: IWP flickr photos)
Linking weather extremes with climate change
Detection and attribution in case of extreme weather events play an important role in understanding climate change better. arathi posted 2 years 7 months ago

Every time an extreme weather event like the Kerala floods occurs, there is a great demand for information on its causes. The question uppermost in public discourse is if such events can be attributed to climate change and global warming.

Whether an extreme weather event can be attributed to climate change or not is a question that has been on the minds of scientists for long. (Photo: IWP Flickr photos)
More water for crops
Subsidies given for irrigation efficiency may have a negative impact on water use. arathi posted 2 years 8 months ago

A new study has pointed out that increased irrigation efficiency does not translate to more water availability for other uses at the watershed level. The subsidies for increasing irrigation efficiency are intended to increase crop production as well as more return flow from irrigated areas that can be allocated to urban, domestic and industrial uses.

Subsidies for irrigation efficiency lead to a decrease in water availability at the watershed level because of increased irrigated areas and water withdrawals. (Pic: IWP Flickr photos)
Western Ghats a source of moisture for monsoon
A new study points out that the evapotranspiration from the vegetation over the Western Ghats accounts for one-quarter of the rainfall over peninsular India. arathi posted 3 years ago

The mountain range that runs along the west coast of peninsular India from Tamil Nadu through Kerala, Karnataka, and Goa to Maharashtra is known as the Western Ghats and is very well known for its majestic beauty. It is also among the top eight biodiversity hotspots in the world.

Western Ghats provides moisture for rainfall. (Source: IWP Flickr photos)
Indian monsoon recovers after decades of decline
Even if the total rainfall recovers, there is no indication that heat waves, droughts, extreme events and widespread floods are about to go away. arathi posted 3 years ago

As the parched Indian subcontinent eagerly awaits the monsoon, all indications are that it will be a normal monsoon, especially since no El Niño is in the offing for 2018. 

Recovering rainfall is a good sign. (IWP Flickr photos)
How marine algae impact global climate, Indian monsoon
Phytoplankton are often early indicators of change in temperatures and can offer potential to extend the lead time of climate predictions. arathi posted 3 years 1 month ago

In a few weeks from now, the seasonal forecast for the Indian summer monsoon will be announced. Among various parameters that determine the fate of the monsoon is the sea surface temperature, more specifically, the contrast between land and sea temperatures. But what are the parameters that determine sea surface temperatures?

One of the parameters that determine the fate of the monsoon is the contrast between land and sea temperatures. (Source: IWP Flickr photos)
Monsoon modelling no ‘blind men and elephant’ story
Though there have been amazing advances in the modelling of weather and climate, no model is perfect. arathi posted 3 years 2 months ago

In a few weeks from now, monsoon forecasts will begin. These forecasts are based on calculations made by computer modelling. There have been amazing advances in the modelling of weather and climate. These include the monsoons, El Niño’s, cyclones, the Inter-Tropical Convergence Zone (ITCZ), winds, currents, and so on. Just as even a new car is not perfect, these models are not perfect.

The current models for monsoon prediction do not always show perfect results due to the intricacies of the monsoon dynamics. (Source: IWP Flickr photos)
Looking for water source
The annual monsoon provides over 200 lakh crore buckets of water. Where does all this water come from? arathi posted 3 years 4 months ago

It rains about 900 mm during a normal monsoon year over India and if we assume that about 80 percent of India is covered by this rain, then the estimated volume of water is well over 200 lakh crore buckets. It comes to two lakh buckets per person. Where does all this water come from? 

A map that shows warm Indian Ocean temperatures in colours and thin contours and blue thick contours that delineate major moisture sources for the monsoon.